title: Patterns of ionic currents around the developing oocyte of the German cockroach, Blattella germanica.
abstract: The development of patterns of current around vitellogenic oocytes of the cockroach, Blattella germanica, was examined by means of a two-dimensional vibrating probe. Previtellogenic oocytes exhibited small unstable currents. Shortly after vitellogenic uptake began (oocytes 0.6-0.8 mm anterior to posterior) currents were either all inward or all outward at the plane of measurement. A dorsoventral pattern of currents was first observed around oocytes a little larger than 0.8 mm. Current exited dorsally (source) and entered ventrally (sink). In these oocytes source and sink were small, less than half the anterior-posterior length. As oocytes grew, relative sizes of source and sink increased until they extended across the major part of dorsal and ventral surfaces. Many late vitellogenic oocytes had a pattern of dorsal outward current with a bimodal distribution. At the onset of chorionation measured currents were again small, unstable, and exhibited no well-defined pattern. Current density was greatest during midvitellogenesis.
authors.affiliation: Department of Zoology, University of Massachusetts, Amherst 01003.
authors.forename: E
authors.initials: E
authors.lastname: Bowdan
authors.forename: J G
authors.initials: JG
authors.lastname: Kunkel
mesh_terms: D000818:Animals; D002823:Chorion / Q000502:physiology; D003058:Cockroaches; D005260:Female; D007477:Ions; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D014732:Vibration; D014819:Vitellogenins / Q000502:physiology
chemical_list: D007477:Ions; D014819:Vitellogenins